U.S. patent number 6,725,941 [Application Number 09/860,622] was granted by the patent office on 2004-04-27 for fire retardant delivery system.
Invention is credited to Paul Edwards, Gregory Ruebusch.
United States Patent |
6,725,941 |
Edwards , et al. |
April 27, 2004 |
Fire retardant delivery system
Abstract
A fire extinguishing and fire retarding method is provided
comprising the step of confining a fire extinguishing and fire
retarding agent in slurry, liquid or gaseous form within a shell
wherein the shell comprises such an agent in solid form. An agent
such as ice water, or liquid carbon dioxide is useful when
employing the shell as "non-lethal" device. The solid shell is
sublimable and will burst upon impact or upon exposure to the
environmental conditions at the target site to release the contents
of the shell as well as the fragments of the shell onto the target
site.
Inventors: |
Edwards; Paul (San Jose,
CA), Ruebusch; Gregory (Mountain View, CA) |
Family
ID: |
22763098 |
Appl.
No.: |
09/860,622 |
Filed: |
May 18, 2001 |
Current U.S.
Class: |
169/47; 169/30;
169/36; 169/46; 169/58; 169/57; 169/56; 169/43 |
Current CPC
Class: |
A62C
19/00 (20130101); A62C 35/10 (20130101); A62C
3/025 (20130101); A62C 3/0228 (20130101); A62C
99/0018 (20130101) |
Current International
Class: |
A62C
3/00 (20060101); A62C 35/10 (20060101); A62C
35/00 (20060101); A62C 3/02 (20060101); A62C
39/00 (20060101); A62C 19/00 (20060101); A62C
002/00 (); A62C 003/00 () |
Field of
Search: |
;169/30,36,43,46,47,48,49,50,56,57,58,89 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Evans; Robin O.
Attorney, Agent or Firm: Fish & Richardson P.C.
Parent Case Text
This application claims benefit of Provisional Ser. No. 60/205,656,
filed May 18, 2000.
Claims
What is claimed is:
1. An apparatus for forming a projectile comprising: a shaped
molding cavity for receiving a fluid to form a shell in the shape
of said cavity; a first conduit for directing a cooling agent for
cooling said cavity to solidify said fluid thereby forming said
shell; a second conduit for filling said shell with liquid, slurry
or gaseous contents; and a first compression piston for compressing
said shell to seal said liquid, slurry or gas within said shell to
form said projectile.
2. An apparatus according to claim 1 wherein said cavity is in a
second piston which is cooled to form said shell.
3. An apparatus according to claim 2 wherein said second piston is
sufficient to withstand pressure necessary to form said shell.
4. An apparatus according to any of claims 1 through 3 wherein said
cavity is defined by a surface comprising ridges to form
indentations on said shell.
5. A method of extinguishing or retarding fire, said method
comprising: confining a fluid fire extinguishing or fire retarding
agent in liquid, slurry or gaseous form within a container, said
container comprising a shell comprising a solid fire extinguishing
or fire retarding agent, wherein said solid agent comprises solid
carbon dioxide; and delivering said container in close proximity to
burning substances in said fire, whereby said container ruptures to
release said solid and fluid agents in liquid, solid or gaseous
form onto said burning substances.
6. The method according to claim 5, wherein said solid and fluid
agents comprise carbon dioxide.
7. A method of forming a projectile, said method comprising:
forming a shell of predetermined shape and size, said shell
comprising a solid fire extinguishing or fire retarding agent,
wherein said solid agent comprises solid carbon dioxide; filling
said shell with a core comprising a fluid fire extinguishing or
fire retarding agent in liquid, slurry or gaseous form; and sealing
said shell.
8. The method according to claim 7, wherein said solid and fluid
solid agents comprise carbon dioxide.
9. A crowd dispersal method, comprising: confining a fluid
non-lethal solid agent in liquid, slurry or gaseous form within a
container, said container comprising a shell comprising a
non-lethal agent in solid form, wherein said solid agent comprises
solid carbon dioxide; and delivering said container in close
proximity to persons in a crowd, whereby said container ruptures to
release said solid and fluid agents.
10. The method according to claim 9, wherein said solid and fluid
agents comprise carbon dioxide.
11. A method of forming a projectile, said method comprising:
forming a shell of predetermined shape and size, said shell
comprising a solid non-lethal agent wherein said solid agent
comprises carbon dioxide; filling said shell with a core comprising
a non-lethal fluid agent in liquid, slurry or gaseous form; and
sealing said shell.
12. The method according to claim 11, wherein said solid and fluid
agents comprise carbon dioxide.
13. A container for delivering a fluid material into a target
environment, said container comprising: a shell comprising solid
carbon dioxide; and a fluid material in liquid, slurry or gaseous
form confined within said shell.
14. The container of claim 13 wherein said fluid material comprises
carbon dioxide.
15. The container of claim 13 wherein said fluid material comprises
water.
16. The container of claim 13, wherein said fluid material is
confined under pressure within said shell.
17. A container for delivering a fluid material into a target
environment, said container comprising: a shell comprising ice; and
a fluid material in liquid, slurry or gaseous form confined within
said shell, wherein said fluid material comprises carbon
dioxide.
18. The container of claim 17, wherein said fluid material is
confined under pressure within said shell.
19. A method of delivering a fluid material into a target
environment, said method comprising: confining a fluid material in
liquid, slurry or gaseous form within a container, said container
comprising a shell, wherein said shell comprises solid carbon
dioxide; and delivering said container into a target environment,
whereby said container ruptures to release said fluid material in
liquid, slurry or gaseous form into said target environment.
20. The container of claim 19, wherein said fluid material
comprises carbon dioxide or water.
21. The container of claim 19, wherein said fluid material is
confined under pressure within said shell.
22. A method of forming a projectile, said method comprising:
forming a shell of predetermined shape and size, wherein said shell
comprises solid carbon dioxide; filling said shell with a fluid
material in liquid, slurry or gaseous form; and sealing said
shell.
23. The container of claim 22, wherein said fluid material
comprises carbon dioxide or water.
24. The container of claim 22, wherein said fluid material is
confined under pressure within said shell.
Description
The present invention is an embodiment of the designed phase-change
canister material delivery system as applied to a fire
extinguishing method and system in which the delivery capsule is
formed by confining a fire extinguishing agent within a designed
phase change container comprising the shell of a fire extinguishing
agent in solid form. The container is delivered and allows
delivery, in close proximity to burning substances such that
release of the agent from the ruptured container and the container
itself extinguishes or suppresses the fire.
BACKGROUND OF THE INVENTION
The present invention provides a fire extinguishing and fire
retardant delivery method and system to suppress and extinguish
fires, in particular, wildfires. Wildfires, which include forest
and range fires, are fully self-sustaining and are either of such a
size or in such a location, which make them unmanageable by
conventional means. Current technologies for wildfire suppression
are fuel starvation and/or removal and aerial delivery of
suppression agents, such as water and retardant slurries. The
self-sustaining nature of wildfires means that they generate very
large incoming airflows, vertical updrafts and turbulence, which
provide fuel/air sourcing and mixing. These airflow patterns
generated by these fires make it difficult to deliver slurry
retardant and/or water to the core of the fire. Delivery of such
materials to the core of the fire can cool, block infrared
transmission, and deprive the fire of fuel. The system of the
present invention provides a method and means for delivering to a
fire target, a retardant or extinguishing material in a thermal
and/or pressure-sensitive container.
Another direct application of the type of container embodied in
this patent is the use as a non-lethal weapon. The rupture of the
canister can have a stun effect coupled with the disbursement of
material into a crowd.
SUMMARY OF THE INVENTION
A fire suppression or extinguishing method is provided comprising
the step of confining a fire extinguishing or suppressing agent in
slurry, liquid or gaseous form within a phase-change canister which
comprises a shell of such an agent in solid form. The optimum
system uses an agent in solid form which sublimates at atmospheric
pressure at temperatures above about -150.degree. C. The container
is designed and delivered in close proximity to burning substances
such that the container ruptures releasing the agent onto the
burning substance.
The container is formed such that the shell comprises an agent in
solid form and the inner core is filled with an agent in slurry,
liquid or gaseous form.
The container may be made on an apparatus comprising a shaped
molding cavity for receiving the liquid agent to form a shell; a
feature for cooling the surface to solidify the liquid to form the
shell, a feature for filling the shell with the liquid agent and
sealing the shell to form the container, and a feature for
releasing the container from the molding surface. Another apparatus
for forming the container comprises a shaped molding cavity for
receiving the liquid agent to form a shell; a feature to solidify
the liquid to form the shell by a pressure-controlled phase change
and a feature for releasing the container from the molding
surface
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cut-away view of a container according to the
invention for delivery to a fire.
FIG. 2 is a cross-section of an apparatus for preparing the
container shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fire extinguishing or fire retardant agents typically used in
the present invention are materials which can be totally absorbed
and/or dispersed into the target environment, yet which are benign
relative to the target environment. The preferred materials for the
solid shell of the container are solid carbon dioxide, ice or other
solid fire retardant or extinguishing agents. Carbon dioxide and
ice are the preferred materials for use as the shell as a
non-lethal weapon. As explained in more detail below, the container
may be sealed under pressure or it may be unpressurized. The shell
material is selected so that the shell material itself also serves
as a fire extinguishing or retarding agent, thereby enhancing the
effects of the material dispersed from the container. The shell
composition and thickness are designed so that it will weaken or
fail, releasing the enclosed material, either by the phase change
of the shell material, i.e. melting or sublimation, and/or by
bursting of the shell upon impact.
The shell thickness of the container may be readily determined by
those of ordinary skill in the art based on the type of material to
be dispersed, the desired radius of dispersement, the time-delay,
if any, between the placement of the container and the moment of
dispersement, and the target environment conditions for
dispersement of the encased material. A property of the container
wall is that in the target environment it will undergo a change in
phase consistent with that which would readily disperse or be
absorbed by the target environment. Typically, the shell will
change its physical state in accordance with the system state
variables at the target or environment. That is, the shell material
will melt and/or sublime at the temperature or other environmental
conditions at the target site.
The materials may be distributed at the target site by bursting of
the container. For example, a shell of solid carbon dioxide may
contain a core of a liquid dioxide, water, or other extinguishing
agent or fire retarding agent. The shell may also, for example, be
made of ice and contain a core of liquid carbon dioxide, water or
other extinguishing agent or retarding agent. Furthermore, the
shell may be made of a solid retardant and/or extinguishing agent
and the core may contain liquid carbon dioxide, water, or other
extinguishing agent and/or retarding agent. The contents may be
pressurized or not, depending on the timing of the burst, desired
radius of dissipation or desired dispersion method. Typically, the
core material will be sublimable at a temperature above about
-150.degree. C. up to about 100.degree. C. The bursting of the
container due to changes in environmental conditions or impact at
the target site is much more desirable than the use of explosives.
Explosive bursting charges are environmentally unacceptable, can
add undesirable debris to the environment and generate incendiary
materials as a result of the explosion process.
Another method of release of the materials is by diffuision mixing.
The material within the container, i.e. bacterial agents or
chemical agents may be diffuision driven for dispersion and thus
may require a release mechanism involving the erosion of the
container wall.
Finally, release may be triggered by an environmental effect, such
as thermal or pressure activation such that the thermodynamic and
mechanical properties of the shell and the contents serve as
rupture triggers within the container.
The containers may be delivered from aircraft or thrown or shot
into the target area using catapults, air pressure guns and the
like.
Referring to FIG. 1, there is shown a partial cutaway of one
embodiment of a container according to the present invention. The
container comprises a shell (10) and a hollow interior containing a
slurry, liquid or gas of a fire extinguishing or fire retarding
material (11). The shell (10) is also made of a fire extinguishing
or retarding material. Indentations (10a) serve to facilitate
release of the container from the mold from which it is made.
Preferably, the container is of a relatively large size, having an
interior volume determined by the fire suppression application. It
can carry charges of sufficient amounts of material such as carbon
dioxide, which will at room temperature be converted into a large
volume of gaseous carbon dioxide and some liquid carbon dioxide.
The vapor pressure of liquid carbon dioxide rises with temperature,
and can reach approximately 1,000 atmospheres at temperatures of
about 160.degree. C. Thus, the containers in the practice of the
invention when using carbon dioxide as an interior component should
be constructed to resist rupture when introduced into a fire until
the maximum internal stress in the shell wall is exceeded by either
or both the internal pressure built up or external forces. In
practice, the charged container is introduced into the fire by
being dropped, thrown or shot into the blaze. The heat of the fire
primarily reduces the shell thickness, and thus its overall
strength to a point where the internal pressures cause shell
rupture and disburse the contained material. This is assuming that
the shell was not designed to rupture on impact. The heat of the
fire raises the temperature slightly within this container design.
The container explodes spreading the contents into the surrounding
area. The liquid and gaseous contents expand rapidly with the
liquid material phase changing to gaseous, thus chilling the
surrounding area as well as displacing hot gases and replacing them
with CO.sub.2. The contents of the container, as well as the
shattered container particles are rapidly vaporized to provide a
blanket in the target area which serves to smother and extinguish
the blaze.
The process of the invention may be employed with containers of
varying size, from those which are very small, which may be
manually thrown or dropped into the fire to those which must be
either mechanically catapulted to the fire or dropped from an
aircraft or balloon suspended above the fire.
Referring to FIG. 2, there is shown an apparatus for forming a
container according to FIG. 1 by controlled temperature time phase
transition. For convenience, only half of the apparatus is shown
with the mirror image of the other half (not shown) required to
make a complete container. There is a piston (12) having a surface
(13) in the shape of desired shape of the container with ridges
(not shown) that form indentations such as (10a) in the exterior
surface of the shell which serve to promote release of the shell
from the mold. This piston can be cooled with a cooling agent such
as liquid nitrogen, which is introduced through conduit (14). The
piston (12) is compressed to form the shell from fluid (liquid,
slurry or gaseous) initially introduced through line 15. The shell
is then filled through conduit (15) with the liquid, slurry or gas
materials intended to comprise the core. The sealing piston (16) is
utilized to seal the contents within the shell. The forming and
sealing pistons (12) and (16) are then withdrawn, respectively,
from each half of the formed container and the container is
released from the surface (13). Alternatively, a solid shell can be
formed using a similar apparatus having walls sufficient to
withstand the necessary pressure for a controlled pressure-time
phase transition.
As shown, the liquid nitrogen coolant is supplied from pressurized
tank 17 where it is collected in depressurized traps 18. Excess
nitrogen gas is vented through vent 19.
Carbon dioxide is supplied from tank 20 from which it is filtered
through filter 21 and depressurized in traps 22. The carbon dioxide
which will be frozen to form the shell of the canister is
introduced via conduit 23 to surface 13. The carbon dioxide which
will form the liquid/gas/solid contents of the container is
introduced via line to conduit 15.
The hydraulic system for manipulating pistons 12 and 16 is provided
by hydraulic fluid storage tank 24 and pump 25. The flow of
hydraulic fluid is controlled by valve controllers 26 to compress
pistons 16 or 12, respectively, by pressuring compartments 26 or
27. The pistons 16 or 12 are withdrawn, respectively, by pressuring
compartments 29 or 28.
Materials other than carbon dioxide may be utilized in tank 20,
such as water or aqueous slurries or solutions of fire retardant
agents.
It is understood that certain changes and modifications may be made
to the above containers and apparatus without departing from the
scope of the invention and it is intended that all matter contained
in the above description shall be interpreted as illustrative and
not limiting the invention in any way.
* * * * *